Figure 2.

A, SOCC activity was examined in JOE OPCs pretreated with Tg in the presence of zero Ca²⁺ medium. B, The increased Ca²⁺ response in JOE cells, after reexposure to 2 mm Ca²⁺-containing medium, was totally abolished in 25 μm 2-APB. C, Similar results were found using 10 μm MRS-1845, a specific blocker of store-operated Ca²⁺ entry. Note that each trace corresponds to a single OPC. The times of addition of Tg-, 2-APB-, MRS-1845-, and Ca²⁺-containing external solutions are indicated by the horizontal bars. D, The increased Ca²⁺ response in JOE cells was insensitive to treatment with 10 μm Cd²⁺ or 25 μm verapamil and was abolished in 1 μm La²⁺, 25 μm 2-APB, and 10 μm MRS-1845. The graphs show the average amplitude calculated from the responding cells, expressed as percentage of change of the emission intensities. Values are expressed as mean ± SEM of at least four independent experiments (n > 400 cells for each condition). **p < 0.01 versus respective controls.